This is in no way a criticism, but it depends on the use the material is being put and the surface finish required.

If the part being made is strength critical then, yes, you need the resin manufacture's curing data.

However, if the part is cosmetic or non structural, then a little experimentation will suffice. I am assuming here that the resins used in fibreglass prepreg are similar to those used in carbon prepreg.

Lay up a small sample and cure at around 120 deg C as most resins will cure at this temp (bring to this temp at 3deg C a minute) for around 3 hours. If the surface is pinhole free enough for your purpose, then carry on. If not, then try a lower temp for a longer time or a two stage cure - bring up to 80 deg C, keep here for 30 minutes, then continue to 120 and leave for 2-3 hours. At 120 deg C you can't really over cure.

I have used resins designed for Autoclave only in my normal oven, using a method suggested by the supplier, so there is some flexibility to the curing process.

This is in no way scientific, but has worked for me. I'm not making strength critical parts and I am painting them to hide the fact that they are carbon.

Having said all this, the simplest way (as Hanaldo says), assuming that you know the origin of the material, is to ask the resin manufacturer :-)